Syringe injector

Abstract

A syringe injector for injecting liquids into patients comprising a syringe barrel with a slidable piston therein and a driver slidably extending into the barrel bore from the open end thereof behind the piston, where the driver includes a power supply and drive means operated by the power supply to cause at least a portion of the driver to move relative to the barrel to engage and propel the piston toward the discharge opening in the syringe barrel.

What is claimed as invention is: 
     
       1. A syringe injector for injecting liquids into patients comprising: a syringe barrel defining a cylindrical bore therein opening onto one end thereof and a discharge opening in the other end thereof communicating with said bore;   a piston slidably mounted in said bore and in sealing engagement with said barrel for movement toward said discharge opening to force liquid in said bore between said piston and said discharge opening out through said discharge opening; and   a driver slidably extending into said barrel bore from the open end thereof behind said piston, said driver including: a housing having a projecting end and a trailing end, said housing defining external threads therearound at the projecting end thereof;   an internally threaded tubular plunger screwed onto the external threads on said housing and extending over said housing so that, when said driver extends into said barrel bore with the projecting end of said housing facing said piston, said plunger engages said piston and moves said piston toward said discharge opening as said plunger is unscrewed from over said housing;   locking means adjacent the trailing end of said housing to selectively engage said barrel and fix said housing axially of said barrel bore;   a power supply; and   drive means operated by said power supply, said drive means including a drive shaft projecting from the projecting end of said housing and oriented coaxially of said plunger and a drive wheel mounted on said drive shaft adjacent the projecting end of said housing for rotation with said drive shaft, said drive wheel including at least one drive lug thereon and said plunger defining at least one longitudinally extending slot therein into which said drive lug projects so that, when said drive means rotates said drive shaft and said drive wheel, said drive lug rotates said plunger to unscrew said plunger from over said housing to cause said plunger to move relative to said barrel to engage and propel said piston toward said discharge opening.     
     
     
       2. The syringe injector of claim 1 wherein said drive means further includes an electric motor rotating said drive shaft and wherein said power supply includes a battery electrically connected to said motor to operate same.